So is the panoramic and paralax the same feature? I keep hearing both being used interchangeably. Does the GM have any sort of new wallpaper parallax or is it a plain ol' static image?

Not really. The parallax effect is the obvious "layers" that are apparent by slight rotations of the device - how the background seems to move (slightly) to reveal other details of the background, icons, badges, etc.

The panorama effect is similar but actually scrolled across a large, panoramic photo (set as a wallpaper) behind the lock screen or the icons.

The parallax effect is still present in the GM release... but the panorama effect is not.